Prevention of dental caries is a key focus of research activities of staff. Both fluorides and dental sealants are topics of research investigation and science transfer. Research activities have been undertaken by staff regarding the use of fluoride and dental sealants including publications on the use of fluoride products by children under the age of two years, a vital and health statistic monographs and three journal articles on caries preventive behaviors in the U.S. and an analysis of community based sealant programs. Even when dental caries prevalence has declined markedly in population groups exposed to beneficial levels of fluoride, decay in the pits and fissures of teeth persists as a problem. Such was the case in rural Nelson County, Virginia, where after 11 years of a school-based program of self-applied fluoride therapy, 92 percent of the remaining decay was confined to the pits and fissures. Final examinations for dental caries experience (DMFS index) were conducted in the fall of 1983. At this time, a dental sealant program was added to the ongoing fluoride program. Children ages 6-7 and 12-13 were eligible to receive pit and fissure sealants on their teeth. Dental caries data from the fall examination served as baseline information for those children who participated in the sealant phase of the study. In succeeding years, new groups of 6- and 12-year-olds were enrolled in the project. Treatments continued for four years. Final examinations were conducted in September 1987. After four years, the overall mean caries score for 416 children who received dental sealants and fluorides was 51 percent lower than the comparable score for 762 children (the same ages four years earlier in 1983) who received fluoride therapy only. A manuscript describing findings for dental caries and retention of dental sealants has been submitted for publication. Based on extensive literature review and analytic projects described above, staff are designing a cost effectiveness study of dental sealants to be begun next year.